A more thorough explanation:

When someone acknowledges their right to a property, it is called a "fine sur cognizance de droit, come ceo que il ad de son done". This was a common way of transferring property ownership in the past. The person who was giving up the property (called the deforciant) would acknowledge in court that they had already given the property to the new owner (called the cognizee). This was done instead of physically giving the property to the new owner. This type of transfer was called a "fine" and was used instead of a livery of seisin.

An example of a "fine sur cognizance de droit come ceo que il ad de son done" would be if John wanted to give his house to Jane. Instead of physically giving her the house, John would go to court and acknowledge that he had already given the house to Jane. This would transfer ownership of the house to Jane.

Another example would be if a father wanted to give his land to his son. The father would acknowledge in court that he had already given the land to his son, and this would transfer ownership of the land to the son.

The examples illustrate how a "fine sur cognizance de droit come ceo que il ad de son done" was used to transfer ownership of property. Instead of physically giving the property to the new owner, the previous owner would acknowledge in court that they had already given the property to the new owner. This was a common way of transferring property ownership in the past and was used instead of a livery of seisin.